Regenerative braking energy utilization by multi train cooperation

Regenerative braking system is widely used on subway trains, which will transmit kinetic energy of the trains to electricity. When the braking speed of a train is comparatively high, regenerative braking is prior to the mechanical braking. However, if the regenerative braking energy can not be absorbed by other trains in the same power supply section, the regenerative braking energy may lead to the voltage rising, even have to use dissipative resistance to absorb the surplus energy. The expected situation is that the regenerative braking energy is absorbed by other trains in the same power supply section as much as possible. Multi-train cooperation method is given in this paper, where the speed profile of the trains, selected to absorb the regenerative braking energy, will be partly adjusted. Typically, part of the original speed profile will be replaced by coast-accelerate-coast strategy, the objective is to make the train run as far as possible by only using the distributed regenerative energy. A case is studied based on Beijing Yizhuang Subway line, where speed profiles of two trains are adjusted to absorb the regenerative braking energy generated by a braking train at the same power supply section.